Colorimetric assay of Hg2+ based on the inhibition of peroxidase mimetic activity of gold nanoclusters induced by Hg2+

[摘要] In this paper, we report a highly sensitive and selective colorimetric assay for Hg2+ detection in aqueous solutions. Bovine serum albumin–gold nanoclusters (BSA–AuNCs) were prepared and used as a mimetic peroxidase to catalyze the 3,3′,5,5′-tetramethylbenzidine (TMB)–H2O2 system. In the absence of Hg2+, the AuNCs catalyze the reaction between TMB and H2O2, leading to a color change from colorless to blue. In the presence of Hg2+, owing to high-affinity metallophilic interactions between Hg2+ and Au+ on the surface of the AuNCs, Hg2+ can decrease the catalytic ability of the AuNCs, resulting in a decreased color change. The color changes in varying degrees depending on the concentration of Hg2+. The method shows low detection limits for Hg2+: 3.0 nM in deionized water and 3.5 nM in lake water.

[学科分类] 分析化学